A new feature is available that enables Outlook 2007 to use DNS Service Location (SRV) records to locate the Exchange Autodiscover service

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INTRODUCTION

This article describes a new feature in Microsoft Office Outlook 2007. This new feature enables Outlook 2007 to use DNS Service Location (SRV) records to locate the Exchange Autodiscover service.

This feature is also available in Outlook 2010.

More Information

Update Information

A supported feature that modifies the default behavior of the product is now available from Microsoft, but it is only intended to modify the behavior that this article describes. Apply it only to systems that specifically require it. This feature may receive additional testing. Therefore, if you are not severely affected by the lack of this feature, we recommend that you wait for the next Outlook 2007 service pack that contains this feature.

To obtain this feature immediately, download the feature by following the instructions later in this article or contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

This feature is available as part of the following update rollup for Outlook 2007:

939184 Description of the update rollup for Outlook 2007: June 27, 2007

Background

When Outlook 2007 is not domain-joined, you have to use a predefined URL method or an HTTP redirect method in order to locate the Autodiscover service. The following list contains two predefined URL methods and one HTTP redirect method:

https://<smtpdomain>/Autodiscover/Autodiscover.xml

https://autodiscover.<smtpdomain>/Autodiscover/Autodiscover.xml

http://autodiscover.<smtpdomain>/Autodiscover/Autodiscover.xml

Note The predefined URL method requires that you have a valid SSL certificate for the URL that you are using. This method can be difficult to implement because you generally use one DNS name for the Outlook Anywhere feature for Microsoft Exchange Server 2007 and a different DNS name for Microsoft Office Outlook Web Access.

Note The HTTP redirect method can be difficult to implement because it requires the following in order to work correctly:

An additional Web site in IIS

Two Public IP addresses

By using the software update that is described in this article, Outlook 2007 will perform an additional check for a DNS SRV record in order to locate the Autodiscover service. This additional check does not require complex configuration or a valid certificate for the Autodiscover service.

How to use the new DNS SRV lookup method to locate the Exchange 2007 Autodiscover service

To use the new DNS SRV lookup method in order to locate the Exchange 2007 Autodiscover service, follow these steps.

Note You must create the Autodiscover SRV record in the external DNS zone that matches the right side of your user's SMTP addresses. For example, if a user's primary SMTP address is user@contoso.com, the record must be created in the contoso.com external DNS zone. If you have multiple primary SMTP address domains in your organization, you must create an Autodiscover SRV record in each zone.

In your external DNS zone, remove any HOST (A) or CNAME records for the Autodiscover service.